It is already known in the prior art, in particular from FR 2 946 307, a railway vehicle bogie comprising two pairs of wheels, the wheels of each pair being connected to each other by an axle structure. The bogie also includes an articulated chassis, supporting the axle structures through the primary suspension means.
It should be noted that a chassis is called “articulated” when it has two parts (or half chassis) that are connected and articulate relative to one another about an axis. Such an articulated chassis makes it possible to limit wheel unloading induced by track defects (also called “track twists”). Thus, the articulated chassis enables the bogie to overcome the track twists, that is to say, it may have ground control points that are not in the same running plane.
When the bogie is designed to equip a low floor railway vehicle, the vertical space requirement of the suspensions should be relatively reduced. To this end, the suspensions are generally formed by resilient bodies made of elastomeric material, in particular rubber, which are compact and space saving.
However, such elastomeric members lose effectiveness over time. In addition, the effectiveness of these elastomeric members is also reduced when their temperature is very high or very low, which can occur when the train is travelling through a country having hot or cold weather.